Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!pilchuck!dataio!bright
From: bright@Data-IO.COM (Walter Bright)
Newsgroups: comp.os.msdos.programmer
Subject: Re:  Accessing VGA memory inside INT 0x33  FUNC 0x0c
Keywords: VGA, MOUSE, INTERRUPTS
Message-ID: <2695@dataio.Data-IO.COM>
Date: 7 Sep 90 18:45:49 GMT
References: <15188@shlump.nac.dec.com>
Organization: Data I/O Corporation; Redmond, WA
Lines: 10

In article <15188@shlump.nac.dec.com> heintze@grane.enet.dec.com (Siegfried Heintze) writes:
<   Hurray, hurray - I have, after many late nights and much tribulation,
<   found the problem:   ZORTECH's sleep function (V2.1 or later, V2.0x seems
<   fine) causes hangs or calls to exit(0) when INT 0x33 FUNC 2 or INT 0x10 FUNC
<   9  is called from the routine whose address is passed INT 0x33 FUNC 0x0c.

Zortech's sleep function is implemented as a simple loop that calls the
DOS get time of day function in a tight loop until the specified time
has elapsed. Unfortunately, DOS and the BIOS are not reentrant, so
calling DOS or the BIOS while in sleep could cause a crash.